Fluorescent diagnosis of urinary bladder cancer-a comparison of two diagnostic modalities

White light cystoscopy (WLC) is considered to be a standard examination for localisation and surveillance of transitional cell cancer of urinary bladder. However, in patients who have undergone transurethral resection of bladder tumour (TUR-BT) sensitivity of this method is too low for early detection of cancer recurrence. In order to improve this unsatisfactory situation new diagnostic procedures are still under investigation. Fluorescent diagnosis is a modern diagnostic option based on the detection of distinctive fluorescence of normal and pathological tissue. Currently two techniques are in clinical use: autofluorescent diagnosis, also termed laser-induced fluorescence (LIF) and photodynamic diagnosis (PDD). In this study we have analysed sensitivity and specificity of the fluorescent diagnosis to validate the best mode of bladder cancer diagnosis. A total of 281 patients, after electroresection of bladder tumour due to transitional cell carcinoma, without any signs of tumour recurrence in white-light cystoscopy, were divided in two groups: 52 patients underwent PDD and in 229 patients autofluorescent diagnosis was performed. Bladder washings and excisions from suspicious red fluorescent spots were taken for histopathological and cytological analyses. Sensitivity and specificity of PDD equalled to 90.91 and 66.60%, respectively. In case of autofluorescence diagnosis these values amounted to: 97.83 and 70.07%, respectively. The overall sensitivity and specificity of fluorescent examination equalled to 96.49 and 69.46%, respectively.

Autofluorescence diagnosis (LIF) of pathological lesions within urinary bladder has been proven to be more sensitive than PDD as evaluated by a non-parametrical test for structure indicators comparison (LIF versus PDD, P=0.0056).